Congestive heart failure (CHF) is a disease state characterized by an enlargement of the heart with a concomitant reduction in pumping efficiency. Treatment regimes for CHF have included drugs, specifically diuretics, as well surgical interventions to remodel the heart. More recently it has been shown that pacing both ventricular chambers of the heart is close temporal sequence can improve the cardiac performance for CHF patients. It is believed that conduction disturbances contribute to CHF and replicating a “normal” activation sequence will improve heart function reducing or relieving symptoms.
The primary variables in biventricular pacing are the A-V delay and the V—V right and left ventricular pacing delay. In general the pacer synchronizes with the atrium and paces both ventricular chambers in sequence (V—V) after an appropriate A-V delay.